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\begin{pspicture*}(-3,-5)(3,36)
\footnotesize
\psaxes[arrows=<->,Dy=5](0,0)(-2,-1)(2,35)
\psplot[linecolor=blue]{-2}{2}{0}
\rput[l](2.1,0){$C=0$}
\psplot[linecolor=blue]{-2}{2}{2.7183 x exp}
\rput[l](2.1,8){$C=1$}
\psplot[linecolor=blue]{-2}{2}{2.7183 x exp 2 mul}
\rput[l](2.1,15){$C=2$}
\psplot[linecolor=blue]{-2}{2}{2.7183 x exp 3 mul}
\rput[l](2.1,22){$C=3$}
\psplot[linecolor=blue]{-2}{2}{2.7183 x exp 4 mul}
\rput[l](2.1,29){$C=4$}
\psplot[linecolor=red]{-2}{2}{2.7183 x exp 5 mul}
\rput[l](2.1,35){$C=5$}
\end{pspicture*}